conrad



N. l. CONRAD.

SPARK INDICATOR AND INTENSIFIER. APPLICATION FILED APR. 29. me.

1 ,3 1 6, 560 Patented Sept. 23, 1919.

4 SHEETS-SHEET I.

- Z72Z/67ZZ157 fi cfzcias (rzrtzd By WMVJMM/ N.-J. CONRAD.

SPARK INIHCATOR AND INTENSIFIER.

APPLICATION FILED maze. 1915.

1,316,560. PatentdSept. 23,1919.

41 4 SHEETS-SHEET 2.

N. J. CONRAD.

SPARK \NDICATOR AND INTENSWHKRM APPLICATION FILED APR.29,1916.

1 ,3 1 6, 560. Patented Sept. 23, 1919.

4 SHEETS-SHEET 3- N. J. CONRAD.

SPARK INDICATOR AND INTENSIFIER.

AFRLICATION FILED APR. 29.1916.

Patented Sept. 23, 1919.

4 SHEETSSHEET 4- 17222872 jZzcizoZas cf Cbnrad UNITED STATES PATENTOFFICE.

NICHOLAS .I. CONRAD, or CHICAGO, ILLINOIS, ASSIGNOIR. T SGHWEITZER &CONRAD, or

CHICAGO, ILLINOIS, A oom-ona'rxon or IL moIs. I

SPARK INDICATOR AND INTENSIFIER Specification of Letters Patent.Patented Sept. 23, 1919.

Application filed April 29, 1916. Serial No. 94,361.

full, clear, concise, and exact description,

- reference being had to the accompanying drawings, forming a part ofthis specification.

My invention relates to ignition! mechanism for internal combustionengines and the like and more particularly to spark in-' dicating andintensifying mechanisms.

It has been generally recognized for some time that the use of anauxiliary gap in series with the spark plug or ignition gap in theignition circuit of an internal combustion engine or the like, improvesthe operation of the spark plug or ignition gap. This improvement inoperation may be due to the increased steepness of the wave front of thedischarge, or it may be due to some other effect, sufiice it to say thatit is an accepted and easily demonstrable fact. The auxiliary gap offersan additional feature of providing a visual indication of the discharge.As heretofore constructed, these auxiliary gaps have generally taken theform of an attachment to the plug or have been built into the plug andhave generally provided a sight opening or a transparent portion toenable the operator to observe the indication.

Placing the auxiliary gap or intensifier near the plug, or securing theintensifier to the plugs body, enables the operator to observe theaction of the ignition mechanism of the individual cylinder.

I have found that with the intensifiers located at the cylinders it isimpossible to observe the indication of more than one cylinder at a timeand it is further impossible to observe the indication during the timethat it is most valuable, namely, when the car is in motion. I havediscovered also that entirely new, valuable information may be gained bya comparison of the sparks that occur at each of the intensifiers.

My invention provides a structure which makes possible a convenient andeffective comparison of the sparks each with the other in amulti-cylinder engine. Such comparison is particularly valuable where acommon source of current produces each discharge.

It permits of a proper initial adjustment of all of the gaps so that aneven discharge to each plug may be secured and any variation in thesparks thereafter will indicate an abnormal condition.

In carrying out my invention, I group the \intensifiers or indicatinggaps upon a common board which is placed upon the dash of theautomobile, or in general, at thecentral control point in front of theoperator.

In the accompanying drawings, I have illustrated one form of myinvention in which Figure 1 is a partially diagrammatic plan vlew of myinvention applied to the engine of an automobile;

Fig. 2 is a front elevation of one form of I the ignition indicatinginstrument;

Fig. 3 is a vertical cross section of the same;

Fig. '1 is a front elevation of a simplified form of the invention;

Fig. 5 is a detail of construction showing the terminals of theconnecting wires;

Fig. 6 is a front elevation of a modification;

Fig. 7 is a cross section of the same;

Fig. 8 is a front elevation of another modification;

Fig. 9 is a section of the same; and

Fig. 10 is a detail view of a modified form of grounding switch.

In Fig. l I have indicated a six cylinder engine 10 provided with sparkplugs 11 of the usual or any preferred construction, which employ sparkgaps within the cyliin ders of-the engine for igniting the charge. Thecurrent creating the sparks at the spark gaps of the plugs is suppliedby a suitable source of high tension current 12. This source of hightension current '12 operates in connection with a distributer 13 tosupply current to the plugs at the proper time intervals. Lead wires 1%running from the distributer 13 pass into the open end of the conduit 15and are led out from the conduit 15 and provided with suitable terminals16. The ends of the leads 14 which terminate in the terminals 16 have,heretofore in the art,

been connected directly to the spark plugs 11.

I provide a tube or sleeve 17 of insulation which bears suitableterminals or binding posts 18. The binding posts 18 are connected eachto an auxiliary spark gap 1!) by suitable lead wires 20 contained withinthe sleeve or tube 17 The other terminal of the spark gap is connectedbyv means of a wire 21 to the corresponding spark plug 11 so that thegap 19 of each plug circuit is connected in series with thecorresponding spark plug. The auxiliary spark gaps 19 are groupedtogether upon an indicating board 22 which is mounted upon the dashboard23 of the automobile, in front of the driver, in such position that thedriver may view all of the spark gaps simultaneously.

The ignition systems, of many automobiles are arranged so that the orderof firing the cylinder is not consecutive in the positions of thecylinder. I arrange the auxiliary gaps 19 in such order that whatever bethe order of firing the cylinders,

the sparks at the auxiliary gaps will ap-.

pear consecutively-in the group of contacts.

It is apparent that I may group the auxiliary spark gaps in anypredetermined manner so long as the grouping is such that the operatormay observe all of the gaps without shifting the gaze. However, I findit particularly advantageous to group the auxiliary gaps 19 in a circleor according to a closed figure which I designate a circular series.

It is obvious that the wires 20 and 21 may be bare wires. In such casethe sleeve 17 is filled with a suitable insulating compound. It isapparent that the above described arrangement is particularlyadvantageous in applying my invention to existing systems of ignition,since it is necessary only to disengage the terminals 16 of the leads14: from the various spark plugs and connect them to the terminals 18upon the sleeve 17, the terminals of the leads 21 being then connectedto the spark plugs. In installing my invention in new cars, the leads 1L may be connected directly to one side of the auxiliary spark gaps.

I shall now describe the particular construction of the auxiliary sparkgaps l9 and the manner in which they are built up into an indicatingboard or instrument. An annular block or ring 2-5 of insulation isprovided with a number of recesses or apertures 26, corresponding innumber to the spark plugs of the engine. These apertures or recesses maybe formed entirely through the block 25 or may form only a sufficientdepression to house the electrodes of the spark gaps 19. The electrodesfor each aperture are formed as follows: A pair of metallic screws 27and 28 are threaded into suitable holes in the block 25 from the backface thereof. A suitable hole is then drilled radially through the ofthe hole so formed. The pointed screws 29 and 30 project into the recess26 with "their ends adjacent to each other to form v cular block ofinsulating material substan-' tially co-extensive with the block 25. Theinsulated wires 20 and 21 project through holes in the terminal block 35and have mounted at their ends suitable contacts or sleeves 36 which areheld against the terminals 27 and 28 by means of spring washers 37 lyingbelow the collars formed upon the sleeves 36. The collar and the springwasher are preferably sunk in a recess or counter bore, although thesame is not essential. A glass late or front 38 is held over the front 0the block 35 by means of a suitable ring 39. The ring 39 is pro videdwith an inturned flange which overhangs the edge of the glass plate 38to hold the same in position. Suitable felt washers are employed on theedge of the glass plate 38. The ring 38 holds the block 25 and theterminal block 35 in alinement and to this end, in the form shown inFigs. 2 and 3, the ring 39 is internally threaded to cooperate withsuitable threads upon the terminal block 35. A mounting bracket 41 isconnected either to the ring 39 or to theterminal board 35 for mountingthe device upon the dashboard of the automobile or in such otherposition that the operator or attendant may view the action of the sparkgaps to make comparison of the sparks which pass between the differentsets of electrodes.

In the form of device shown in Fig. 4, the ring 39, instead of beingthreaded upon the terminal block 35, is secured thereto by means ofsuitable screws 42.

In the form of device shown in Figs. 2' and 3 an additional or testinggap 43 is provided. This gap comprises a pair of electrodes 44: and 45mounted in a suitable block 46 of insulation. The block 4L6 is securedto a shaft 47 which is connected by means of a collar 48 and a springwasher *9 to a terminal clip, which is connected to the ground wire 50.The electrode id is provided with suitable spring means shown in Fig. 3as a spring-pressed ball for engaging the inner ends of the electrodes30. The electrode 45 is in the form of a pointed screw which is threadedthrough the shaft 47 and is adjustable relative to the terminal 44. Theshaft L7 has secured upon its outer end a knob or handle 52 whichpermits the block 46 to be moved tion of the two devices is similar.

into position to test thecircuit of any one of the spark plugs or to bemoved to an intermediate position where no such test is made. When theadditional or testing spark gap 43 is connected to the electrode 30,'ofone of the spark gaps 19, the testing spark gap forms a shunt of thespark plug. In one form of my invention, as is shown in Fig. 10, thespark gap 43 is replaced by a solid metallic connection. The func- Theadvantage of the additional spark gap l3 is that a visible indication ofthe passage of current to ground is afforded. In the form shown in Fig.4 the ground or testing connection is omitted.

In the form shown in Figs. 6 and 7, I employ a unit construction of thespark gaps 19. In this modification a number of heads '58 and 59respectively, and are adjustable relative to each other. The heads 58and 59 are mounted upon a sleeve or barrel of glass 60. The electrode 56is provided with a jam nut 61 and the end of the electrode passesthrough a bracket 62 which is mounted upon the base 56. A screw 63connects the bracket 62 with one of the lead wires 20.

A thumb nut 64: holds the end of the threaded electrode 56 against thebracket 62. The electrode 57 is provided -with a shoulder 65. Theouterend of the electrode 57 is provided with a loop 66 which is clamped bymeans of a bolt 67 to the plate 5 6. A terminal 68secured to the bolt 67projectsradially inward for a purpose later to be described.

A central testing gap 70 corresponding to the gap 43, shown in Figs. 2and 3 is provided in the form of an additional spark gap unit 71, whichdiffers from the unit structures 55 only in that the electrode 57 has around threaded shank 7-2 instead of a flat eye 66. The electrode 57 isconnected by the wire 50 to ground. The opposite electrode 56 isconnected to a metal spider '73, having radially extending arms 74 InFigs. 8 and 9 I have shown a modification in which one of the electrodesof each of the spark gaps 19 is adjustable, and in which a commonadjusting means is employed to vary the length of the spark gaps 70simultaneously. The outer electrode 76 is mounted in substantially themanner shown in Fi 2 and 3 formounting the electrode 29. lhe end of theelectrode 76 is preferably flat and has the edges chamfered out to forma suitable engaging space for the movable electrode 77 which is slidablymounted in the block of insulation 25 and passes through the terminalscrew 28. The inner end of the electrode 77 projects into the centralspace which is partiallyfilled by a cam member 78. The cam member has anumber of suitable cam faces for engaging the inner ends of theelectrodes 77. The

electrodes 77 are normally held against the faces of the cam member 78by means of the coiled springs 79. The throw of the cams on the cammember 78 is sufficient to move the movable electrode 77 into contactwith the relatively stationary electrode 76. The movableelectrode hasbeen shown in Figs. 8 and 9 at the extreme outward limits in itsmovement. A spring detent 80 holds the cam member 78 yieldingly inposition and a special seat shown at 81 in Fig. 8, is provided forholding the cam member 78 in and those appearing at another gap. Theoperator soon becomes expert at judging and locating the difficultywhich is indicated by the appearance of the particular spark gap whenthe same indicates an abnormal condition. The testing gap is valuable inlocating trouble. Ignition troubles .are very difficult to locate and itis particularly well known that at low speeds, or when the engine isidling, a cylinder will not fire but when the speed of the engine isincreased this failure of firing disappears or reappears onlysporadically. My invention makes it easy to locate the. difliculty andapz'lg the proper remedy regardless of the sp Defects in timing of thefiring of the cylinders are readily made apparent. Variations or defectswhich are imperceptible to the ear even at slow speed or idling arereadily detected by the eye on the above instrument.

The persistency of vision aids materially in making the comparison ofthe sparks. At high speeds the sparks appear rela= tively stationary,and it is easy to make the Comparison.

I do not intend to be limited to the precise details of constructionshown and de 5 scribed, as it is obvious that my invention may appear indifferent forms and that proportions and dimensions are not of theessence of the invention, with the exception of the gaps 19 are to be soclosely placed together as to be visible simultaneously.

What I claim is:

1. In combination, a base-board, a series of auxiliary gaps arranged ina circular group upon said base-board, a plurality of spark plugs, saidauxiliary gaps being connected in series with said spark plugs, andcentral contact means common to all the auxiliary spark gaps forconnecting any one of said auxiliarv spark gaps in series to groundindependently of said spark plu 2. In combination, a base-board, aseries of auxiliary spark gaps arranged in a circular group, a commonspark gap and contact means for connecting said common spark gap inseries with anyone of said auxiliary gaps.

3. In combination, a base-board, a series of auxiliary spark gapsarranged in a circular group upon said base-board, said auxiliary gapsbeing adapted to be connected in series with the spark plugs of anengine, a common spark gap having one terminal connected to ground andcontact means for connecting the other terminal in series with any oneof said auxiliary gaps.

4c. In combination, a plurality of spark plugs, a plurality of auxiliarygaps adapted to be connected in series with said plugs, said auxiliarygaps being arranged in a group, a common spark gap and manual means forconnecting said common gap in shunt of any desired spark plu 5. Incombination, a base-board, a series of auxiliary spark gaps arranged ina circular series upon said baseboard, said board being adapted to bemounted upon the dash-board of an automobile, a tube of insulatingmaterial, a set of terminals connected to the auxiliary gaps, saidterminals being mounted upon said tube and being connected each to anelectrode of the corresponding auxiliary gap, and wires passingthroughsaid tube, said wires connecting the other electrode of each gap to aspark plug of the engine.

6. In combination, a base-board, a series of auxiliary spark gapsgrouped together upon said base-board, said board being adapted to bemounted upon the dash-board of an automobile, a tube of insulating material, a set of terminals, correspondin in number to said auxiliary gapssaid terminals being mounted upon said tube, wires connecting saidterminals with an electrode of the auxiliary gaps, said wires passingthrough said tube, and other wires passing through said tube andconnecting the other electrode of each gap to a spark plug of theengine.

7. In combination, an annular ring of insulating material, said ringhaving recesses therein, electrodes projecting into said recesses, atransparent means covering said recesses, said ring having a centralopening and contact means within the central opening of the ring toconnect the electrodes in parallel with the spark plugs of an engine.

8. In combination, an annular ring of insulating material having acentral opening and having recesses in the front face thereof,electrodes projecting laterally into said recesses to form spark gaps,terminals connecting said electrodes, said terminals being mounted onthe back of said ring, transparent means covering said recesses, acentral rotatable member of insulation having a handle projecting beyondsaid transparent means; and a separate terminal board back of said ring,said terminal board having readily separable connections for connectingsaid spark gaps in series with the spark plugs of an engine.

9. In combination, an annular ring of in sulating material, said ringhaving recesses in the front face thereof, electrodes projecting intosaid recesses to form auxiliary spark gaps, a shaft passing axiallythrough said ring, a body of insulation mounted on saidshaft and lyingwithin the ring, said body of insulation having switch means forcontrolling the effective connection of said electrodes, and transparentmeans covering said recesses, said spark gaps being adapted to beconnected in series with the spark plugs of an engine.

10. In combination, a plurality of spark plugs, a plurality of auxiliaryspark gaps connected in series with said plugs, and switching means forselectively shunting any one of said plugs, said switching meansincluding a testin spark gap.

11. In combination, a plurality of spark plugs, a plurality of. sparkgaps connected in series with said plugs, each of said gaps comprising apair of electrodes, a source of high tension current adapted to beconnected to one of said electrodes of each gap, the other electrode ofeach gap being adapted to be connected to the corresponding spark plug,and selective switching means for connecting said other electrode ofeach gap to ground, said switching means comprising a testing spark gap.

In witness whereof I hereunto subscribe my name this 28th day of April,A. I). 1916.

NICHOLAS J. CONRAD.

